Haversine

Compute the half-value versed sine.

The half-value versed sine is defined as

Installation

npm install @stdlib/math-base-special-haversin

Usage

var haversin = require( '@stdlib/math-base-special-haversin' );

haversin( x )

Computes the half-value versed sine (in radians).

var v = haversin( 0.0 );
// returns 0.0

v = haversin( 3.141592653589793/2.0 );
// returns ~0.5

v = haversin( -3.141592653589793/6.0 );
// returns ~0.06699

Examples

var linspace = require( '@stdlib/array-base-linspace' );
var TWO_PI = require( '@stdlib/constants-float64-two-pi' );
var haversin = require( '@stdlib/math-base-special-haversin' );

var x = linspace( 0.0, TWO_PI, 100 );

var i;
for ( i = 0; i < x.length; i++ ) {
    console.log( haversin( x[ i ] ) );
}

C APIs

Usage

#include "stdlib/math/base/special/haversin.h"

stdlib_base_haversin( x )

Computes the half-value versed sine (in radians).

double out = stdlib_base_haversin( 0.0 );
// returns 0.0

out = stdlib_base_haversin( 3.141592653589793 / 2.0 );
// returns ~0.5

The function accepts the following arguments:

• x: [in] double input value.

double stdlib_base_haversin( const double x );

Examples

#include "stdlib/math/base/special/haversin.h"
#include <stdio.h>

int main( void ) {
    const double x[] = { 0.0, 0.523, 0.785, 1.047, 3.14 };

    double y;
    int i;
    for ( i = 0; i < 5; i++ ) {
        y = stdlib_base_haversin( x[ i ] );
        printf( "haversin(%lf) = %lf\n", x[ i ], y );
    }
}

See Also

• @stdlib/math-base/special/havercos: compute the half-value versed cosine.
• @stdlib/math-base/special/versin: compute the versed sine.

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.